Modern communication systems, particularly military, have to contend with a variety of intentional and unintentional interference sources. Research into methods of contending with these sources of disruption has led to the development of the Interference Detection and Characterization (IDAC) system of this invention. The invention may be implemented via compact, state-of-the-art technology and serve as an add-on unit to existing communications equipment. With its ability to rapidly detect the presence of interference and to isolate signal signatures for characterization, the IDAC system has proven itself to be a valuable tool which provides communications channel monitoring capabilities that until now were not available.
Previous methods used to perform functions similar to those of this invention:
Communications channel monitoring has historically relied on the use of spectrum analyzers to observe RF characteristics within a transmission band. This has provided observers with only coarse information about the transmission band's content since the spectrum analyzer provides a simple magnitude measure of signal power. Because of this, only interference sources with power levels comparable (or stronger) to those of the desired signal could be observed, and even then only very basic information could be gleened as to the type of interferer and its characteristics. In the case of subtle interference, those which could cause a degradation in the bit error rate without causing a loss of receiver lock, the spectrum analyzer would fail to detect its presence since the interferer's power would be buried inside the envelope of the desired signal's power spectrum. Hence, the spectrum analyzer could offer only limited support to the detection and characterization process.
IDAC may be used with new or existing equipment in many ways. In cases where lost systems are sealed and desired signals unavailable, IDAC may be fabricated with its own receiver element to provide proper signal synchronization. This approach would simply require the use of a common IF or RF in order to monitor the desired channel. When new equipment is to be built or existing equipment can be modified, the IDAC architecture can use available signals from that receiver thereby reducing IDAC to a set of processors. The following description deals with the more extreme case where an IDAC receiver must be supplied but both cases are valid under this application.